scholarly journals Transuranics Transmutation Using Neutrons Spectrum from Spallation Reactions

2015 ◽  
Vol 2015 ◽  
pp. 1-23 ◽  
Author(s):  
Maurício Gilberti ◽  
Claubia Pereira ◽  
Maria Auxiliadora F. Veloso ◽  
Antonella Lombardi Costa
Keyword(s):  
Simple Model ◽  
Neutron Spectrum ◽  
Hybrid System ◽  
Target Material ◽  
Neutron Fission ◽  
Spallation Target ◽  
Transport Code ◽  
Spallation Reactions ◽  
Fission Spectrum ◽  
Neutron Fission Spectrum

The aim is to analyse the neutron spectrum influence in a hybrid system ADS-fission inducing transuranics (TRUs) transmutation. A simple model consisting of an Accelerator-Driven Subcritical (ADS) system containing spallation target, moderator or coolant, and spheres of actinides, “fuel,” at different locations in the system was modelled. The simulation was performed using the MCNPX 2.6.0 particles transport code evaluating capture(n,γ)and fission(n,f)reactions, as well as the burnup of actinides. The goal is to examine the behaviour and influences of the hard neutron spectrum from spallation reactions in the transmutation, without the contribution or interference of multiplier subcritical medium, and compare the results with those obtained from the neutron fission spectrum. The results show that the transmutation efficiency is independent of the spallation target material used, and the neutrons spectrum from spallation does not contribute to increased rates of actinides transmutation even in the vicinity of the target.

Simulating the neutron-fission spectrum with a Po-Be source

1969 ◽  
Vol 27 (2) ◽  
pp. 876-877
Author(s):  
V. A. Kryzhanovskii ◽  
V. V. Terekhin
Keyword(s):  
Neutron Fission ◽  
Fission Spectrum ◽  
Neutron Fission Spectrum

scholarly journals Tunable EOS Material Model in the Simulation of Pulsed Mercury Spallation Target Vessel

2019 ◽  
Author(s):  
Lianshan Lin ◽  
Drew Winder
Keyword(s):  
Complex Dynamics ◽  
Target Material ◽  
Material Model ◽  
High Energy ◽  
Material Behavior ◽  
Significant Discrepancy ◽  
Spallation Target ◽  
Energy Pulse ◽  
Measured Strain ◽  
Strain Responses

Abstract A pulsed spallation target is subjected to very short (∼1μs) but intense loads from repeated proton pulses. The effect of this pulsed loading on the stainless-steel target module that contains flowing mercury target material is difficult to predict. Different simulation approaches and material models for the mercury have been tried. To date the best matching simulation to the experimental data was obtained by an equation of state (EOS) material model with a specified tensile cutoff pressure, which simulates the cavitation threshold [1]. The inclusion of a threshold to represent cavitation was a key parameter in achieving successful predictions of stress waves triggered by the high energy pulse striking the mercury and vessel. However, recent measurements of strain responses of target modules showed that significant discrepancy between the measured strain and simulated value with the EOS mercury model still exists. These differences grow to irreconcilable values when non-condensable helium gas is intentionally injected into the flowing mercury. A novel EOS mercury model embedded into ABAQUS VUMAT has been investigated in this project, which introduces the concept of proportional, integral, and derivative (PID) control into the mercury EOS model. By tuning the new introduced PID parameters (Kp, Ki and Kd), we replace the specified cutoff pressure with an adjustable spring-damper-like material behavior which may better match the complex dynamics of the mercury and helium mixture. This approach is expected to reduce the gap between measured and simulated vessel strain responses. Primitive application of this tunable EOS mercury model on prototypic shape experimental target has demonstrated its capability and potential of improving mechanical behavior of EOS mercury with cutoff pressure considered.

scholarly journals Radionuclide Chemistry in Nuclear Facilities Based on Heavy Liquid Metal Coolants: Past, Present and Future

2020 ◽  
Vol 74 (12) ◽  
pp. 976-983
Author(s):  
Jörg Neuhausen
Keyword(s):  
Liquid Metal ◽  
Nuclear Reactions ◽  
Nuclear Reactors ◽  
Liquid Metals ◽  
Target Material ◽  
Secondary Compounds ◽  
Heavy Liquid ◽  
Nuclear Facilities ◽  
Spallation Target ◽  
Chemical Behaviour

Heavy liquid metals such as lead and lead bismuth eutectic (LBE) are considered as spallation target material for next-generation neutron sources and as coolant of fast spectrum nuclear reactors that are developed to facilitate more efficient use of nuclear fuel as well as transmutation of long-lived nuclear waste. During the operation of such facilities, the heavy liquid metal will be activated by nuclear reactions. Additionally, fission product radionuclides may be introduced into the liquid metal from leaking fuel pins or by fission of the target nuclei in spallation. The chemical behaviour of these radioactive contaminants in the liquid metal – especially their immediate volatilization or volatilization of formed secondary compounds – may affect the safety of such facilities. The present article summarizes the activities of PSI's Laboratory of Radiochemistry towards a better understanding of the chemistry of potentially hazardous radionuclides in LBE and discusses aspects that need to be addressed in future to support the licensing of heavy liquid metal-based nuclear facilities.

Cross section of the Am241 (n, ?)Am242 reaction for a neutron spectrum similar to the fission spectrum

1971 ◽  
Vol 30 (4) ◽  
pp. 452-454 ◽  
Author(s):  
N. I. Ivanova ◽  
A. N. Kobzev ◽  
N. G. Krylov ◽  
A. A. Lbov ◽  
N. P. Martynov ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Spectrum ◽  
Fission Spectrum

Calculated neutron spectra from 9Be(α, n) sources

1968 ◽  
Vol 46 (13) ◽  
pp. 1527-1536 ◽  
Author(s):  
L. Van der Zwan
Keyword(s):  
Simple Model ◽  
Neutron Spectrum ◽  
Neutron Yield ◽  
Cluster Size ◽  
Energy Losses ◽  
Neutron Spectra ◽  
N Sources ◽  
Similar Peak ◽  
Α Particles

The neutron spectra from 9Be(α, n) sources are calculated for the α emitters 241Am, 210Po,and 239Pu. For a Pu–Be source, peaks are found at neutron energies of 0.75, 1.20, 2.10, 3.15, 4.95, 6.50, 7.75, and 9.65 MeV. Similar peak positions are found for sources made with 241Am and 210Po. The effect of the α-energy losses in the α-emitting material is studied by means of a simple model consisting of clusters of the α-emitting material embedded in a matrix of beryllium. For sources composed of clusters of AmBe13 or PuBe13 in beryllium, the changes in shape of the neutron spectrum are minor as the cluster size is increased from 0.5 to 20 μ. However, for sources consisting of clusters of Pu and Am or Po embedded in beryllium, the spectrum is considerably distorted as the cluster size is varied from 0.5 to 10 μ. The neutron yield per 106 α particles is calculated for sources having Am, Po, or Pu clusters ranging in size from 0 to 20 μ and AmBe13 or PuBe13 clusters ranging from 0 to 40 μ. The percentage of neutrons below 1.5 MeV including the contribution from the multiparticle reaction 9Be(α, αn)8 Be is estimated to be 16% for an AmBe13 type of source and 12% for a PuBe13 type of source, each with a cluster size of 0.5 μ.

Current status of JAERI spallation target material program

2001 ◽  
Vol 296 (1-3) ◽  
pp. 34-42 ◽  
Author(s):  
K Kikuchi ◽  
T Sasa ◽  
S Ishikura ◽  
K Mukugi ◽  
T Kai ◽  
...  
Keyword(s):  
Target Material ◽  
Current Status ◽  
Spallation Target
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